Plane, helicopter collide near DC's Reagan National Airport. What we know.

Editor's note: For the latest updates on the plane crash near DC on Wednesday, Jan. 29, please read Paste BN's live coverage of the rescue and recovery efforts on Thursday, Jan. 30.
A military Black Hawk helicopter and a plane carrying 60 passengers and four crew members collided near Reagan National Airport on Wednesday night, sending rescue crews scrambling to find survivors.
Fireboats were on the scene of the crash in the Potomac River, the D.C. Fire and EMS Department confirmed on X shortly after 9 p.m. First responders are meeting rescuers at the dock to take victims to safety. The Metropolitan Police Department said local police and other agencies were also responding to the scene.
"All takeoffs and landings have been halted at DCA," the Reagan National Airport said in a statement. "Emergency personnel are responding to an aircraft incident on the airfield. The terminal remains open."
President Donald Trump issued a statement on the crash Wednesday night, calling it a "terrible accident."
"May God Bless their souls,” Trump said in the statement. "Thank you for the incredible work being done by our first responders. I am monitoring the situation and will provide more details as they arise."
Here's what we know so far about the developing situation.
How many people were on board AA flight 5342?
American Airlines confirmed that there were 60 passengers and four crew members on board the aircraft.
"Our concern is for the passengers and crew on board the aircraft. We are in contact with authorities and assisting with emergency response efforts," the airline said.
They asked people who believe they may have loved ones on board AA flight 5342 to call American Airlines toll-free at 800-679-8215. Those calling from outside the U.S. can visit news.aa.com for additional phone numbers. Family members in Canada, Puerto Rico or the U.S. Virgin Islands can call 800-679-8215 directly.
Officials have yet to confirm how many people were onboard the the military helicopter.
The District of Columbia Fire and Emergency Medical Services Department said there was "no confirmed information on casualties at this time."
What type of plane and helicopter were involved?
The military aircraft was identified as a Black Hawk Sikorsky H-60 helicopter. It collided with a PSA Airlines Bombardier CRJ700 regional jet being operated by American Airlines that had departed from Wichita, Kansas, according to the Federal Aviation Administration.
Where did the collision occur?
The aircraft crashed in the Potomac River near the vicinity of Ronald Reagan Washington National Airport.
Is DCA airport closed?
The Ronald Reagan Washington National Airport will remain closed Wednesday until at least 11 a.m. ET, Metropolitan Washington Airports Authority Jack Potter said at a news conference.
What caused the collision?
The cause of the crash is currently under investigation by the FAA and National Transportation Safety Board. The NTSB is leading the investigation, according to a statement from the FAA obtained by Paste BN.
When was the last plane crash at Reagan airport?
The last crash at Reagan National Airport occurred on Jan. 13, 1982, when an Air Florida flight took off from the airport, crashed into a bridge and fell into the Potomac River. The crash killed 78 people, according to the History Channel.
When was the last major U.S. airline crash?
The last major fatal U.S. airline crash occurred in 2009. Continental Flight 3407 from Newark, New Jersey to Buffalo, New York crashed into a house just before landing, killing all 49 passengers and crew members onboard.
Where is Reagan National Airport?
Reagan National Airport is located in Arlington, Virginia. It is approximately 5 miles southwest of the U.S. Capitol.
How cold is the Potomac River?
Water temperature in the Potomac River Wednesday night reportedly ranged between 33 to 36 degrees near the crash site, according to AccuWeather. Meteorologists warn the frigid water temperatures pose a high risk for hypothermia for survivors and first responders of the crash.
"Exhaustion or unconsciousness can occur in as little as 15 to 30 minutes," AccuWeather Senior Director of Forecast Operations Dan DePodwin said in a statement.
What is PSA Airlines?
PSA Airlines is a subsidiary of American Airlines. The airline is based in headquartered in Dayton but announced Wednesday that it is moving to Charlotte, according to WCNC. The airline said that it handles 750 departures daily, according to the station.
Attempts to access the PSA Airlines website Wednesday night were rerouted to the American Airlines website.
Contributing: Thao Nguyen, Joey Garrison Paste BN